Assessing Seed Germination and Seedling Vigour in Rice under Different Thermal Regimes
Elena Luyckx1, Ando Lalaina Razafindrazaka1, Arisoa Rajaona2, Folkard Asch1
1University of Hohenheim, Inst. of Agric. Sci. in the Tropics (Hans-Ruthenberg-Institute), Germany
Rice production environments are quite diverse and often cropping calendar options are limited by either water availability or low temperature. Sustainable intensification of rice production systems requires flexibility in the choice of cultivar, sowing date, and management options. In transplanted systems, nurseries provide options to exploit early genotype × environment to the advantage of later development stages. In order to target nursery management to specific systems changes, it is important to know germination and early seedling vigour capacity of genotypes potentially subjected to new growing environments. Therefore, germination capacity, mobilisation efficiency of grain reserves, days to onset of photo-autotrophy and partitioning of early dry matter gains to the different organs was investigated under temperature regimes typical for tropical low altitude (28/20°C day/night) and tropical high altitude systems (20/12°C day/night) for four contrasting irrigated lowland rice genotypes. Rice was grown in wet loamy sand in a climate chamber and was destructively sampled for plant organs and remaining kernel weight for 14 days after seedling emergence in two day intervals.
Keywords: Cold stress, germination efficiency, Oryza sativa, management option, reserve mobilisation efficiency
Contact Address: Elena Luyckx, University of Hohenheim, Inst. of Agric. Sci. in the Tropics (Hans-Ruthenberg-Institute), Garbenstr. 13, 70599 Stuttgart, Germany, e-mail: elena.beguegmx.de